This is not medical advice, just info of how we managed Tommy's PICC line. But first, if the nurse said not to shower, does that mean the PICC line comes out in 7 days? If not, did she tell you the PICC line dressing can only be changed by an RN and must be done every 7 days without delay?
As mentioned above, PICC line shower cover/guards are very useful. We used one for Tommy's. It is bulky but works as long as you purchase one with the hard plastic rim that stretches the material creating a water tight seal. I went beyond that and used Press and Seal wrap around his PICC line too. I first placed a paper towel over the PICC line area, applied the Press and Seal, then slid on the PICC line shower cover and He never got it wet. His PICC line was in for 3 months and never got an infection!
Bottom line, it's up to the two of you to decide what is appropriate and works for you. BUT, oh how I wished I lived near you. I would help you guys out! PICC lines have to be kept as sterile as possible, which is almost impossible, even in a hospital. There really is no sterile environment outside of a laboratory (even O R are not really sterile)
As I said, I'm only offering info on what we did. I don't know your husbands full medical situation, so I can only make suggestions. I can tell you that Tommy passed away Jan 1st this year of pancreatic cancer, and for nearly 2 years before his passing, I learned how to manage and care for a G-tube, J-tube, Biliary Tube and PICC line and the pumps for the PICC line and J-tube. There are several things you will have to do to prep for every thing you do and the clean up with after yo do them. It's time consuming, but necessary. You might surprise yourself with what you can accomplish when it comes to your loved one!
I wish you much success! I will keep you both in my thoughts.
EDIT:: I would also like to mention, I gave two weeks of strong antibiotics through Tommy's PICC line at our home. I have never had medical training but learned everything from physical therapy to PICC line feeding and J-tube feeding and so much more because I loved him that much. When you have always been the family caregiver, you will be amazed at what you will do that you never thought possible! I wish you two comfort and a speedy recovery!